It is necessary to have a better understanding of the dial pattern when we make an external call. It may easily cause hang up issue if we don’t configure it well. Below is the basic knowledge to know.
Dial Patterns in the Outbound Route
The default dial patterns is like this when you first configure the outbound routes.
Patterns: It is a parameter which means the number you dial should match it.
X means one digit (from 0 to 9) can be matched
Z means any digit from 1-9
N means any digit from 2-9
“.”: Means any character including digits, symbol and etc
“!”: With the analog phone it means restrict the digits. “223!” means you have to dial 223, 3 digit only. With IP phone, “223.” equals with “223!” you have to dial at least 4 digits and start with 223, for example 2234.
Strip: defines how many digits you want to skip
Prepend: something what you add it in front of your dialing number
Note: If the pattern is “X.”, you have to dial at least 2 digits.
Technically speaking, we generate a number to send out that consists of the digits you dialed on the phone to the carrier, and prepend number and strip how many digits from the head according to the dial patterns if you configured before sending out.
Frankly, the original numbers you dialed from your IP phones will match the pattern first in the outbound route if it matches the final numbers will be sent to the carrier according to the patterns you configured. If it doesn’t, the call will try to match the second outbound route and go on. So sometimes it is different the original numbers you dial. I will explain you in the following examples.
The working flow:
Dial from Phone >> Dial Pattern Match process >> Prepend and Strip Process >> Number Sent out to Carrier.
The number you should dial should start with 8. And the length of the numbers doesn’t matter.
You can dial out like 811, 83291, 89448384 as long as you start 8.
1. The number you dial should start with any digit from 1 to 9, so dial 0xxxx is not allowed.
2. The final number sent from PBX will skip the first two digit.
3. The length of number doesn’t matter.
Dial 12345678 >> 12345678 >> 345678, the final number sent to the carrier is 345678
1. The number you dial should start with any digit from 2 to 9, so 1xxxxx and 0xxxxx are not allowed
2. The number through PBX will skip the first two digit
3. 063 in prepend will be added before the number after stripping
4. The length of number doesn’t matter
Dial 3456789 >> 3456789 >> 06356789, the final number sent to the carrier is 06356789
1. The number the number you dial should start with any digit from 2 to 9
2. If the analog phone chosen in the the selected box, the length of the number is 4. If the SIP phone is chosen, “!” is same as “.”
2456, 4569, 6859, numbers like those can be sent successfully.
It is a combination of number group, there are 4 legal numbers in it, 198, 298, 398, 498.
You may add more than one dial pattern in the outbound route
Dial Pattern (DID Pattern) in the Inbound Route
When a SIP call comes in, PBX will compare the called number with the DID number in the inbound route if it is filled. If it matches, it will comes in, if not it will go through the inbound list and check one by one.
Caller ID pattern is used to define which caller ID is allowed to call in through this inbound route.
The patterns in “DID Pattern” and “Caller ID Pattern” are same uesd with its in the outbound route.
There is a common scenario which the client wants to call directly lead to particular destination.
In the example, the DID pattern and the destination should be the serial numbers, the quantity should be the same. In this way, call 7788600 will go directly to 100, 7788601 go to 101 and etc.
For more detailed information about DID: DID Instruction